First of all, let’s clarify the concept of a thesis statement. This statement should be your main idea—what you’re trying to prove, but that being said, the thesis statement MUST be something arguable. If it’s not, there’s really nothing to prove is there?
Next, let’s look at your first sentence. You use too many words when fewer would say the same thing and narrow your focus.
Friendship means different things to different people, and sometimes it is something that has to be learned or experienced.
Next, your thesis is not really arguable as the authors you mentioned do seem to focus on “personal issues” and “friendships.” There is nothing to prove in your statement.
Switch it to something you have to prove such as:
In their works, authors Katherine Mansfield, Janet Frame and David Malouf, show friendship to be the best venue for resolving the personal issues to which all readers can relate.
You now have options for organizing your essay. 1)You can develop a section on each author and how he or she develops this in writing; or 2)You can develop a different section for the different “personal issues” and show how the three authors address the individual issue.